Applicants' U.S. Pat. No. 9,129,153 discloses a basketball shot-tracking system. According to this patent, a wrist-worn sensor is first “trained” or calibrated to recognize various shots a player might make, such as jump shots, hook shots, layups, etc. Once the wrist-worn sensor has been calibrated, it monitors the motion of the player's wrist and detects when a shot attempt of a given type has been made. When a shot attempt is made, the wrist-worn sensor sends a message wirelessly to a mobile computing device (smartphone, tablet computer, laptop computer, etc.), which runs an associated shot-tracking program.
In a very simple application, the system could be used to do nothing more than count the number of times the player takes a shot of a given type. This might be useful, for example, for practice or training purposes, where a player wishes to take a certain number of shots of each type.
On the other hand, the number of shots taken, per se, is not often particularly useful information. Rather, it is the player's shooting percentage—i.e., the percentage of shots of a given type that are made successfully—that is more important to know. Therefore, the system disclosed in U.S. Pat. No. 9,129,153 also includes a net-mounted sensor configured to detect when shots have been made successfully, and to transmit that information wirelessly to the mobile computing device. More particularly, the net-mounted sensor disclosed in U.S. Pat. No. 9,129,153 detects shots that have been made successfully by matching the time profile of the magnitude of sensor acceleration to a pre-established normative profile for sensor acceleration magnitude exhibited when a shot has been made successfully, where acceleration magnitude is the square root of the sum of the squares of the sensor acceleration along three orthogonal axes that are fixed relative to the sensor.